Biology subjects

Pribis, J. P.

Publications and source records attributed to Pribis, J. P..

3 recordsLinked to original sources

bioRxiv2022

Starvation Response and RNA Polymerase Guide Antibiotic-induced Mutable Gambler Cells

Antibiotics can induce mutations that cause antibiotic resistance, triggered by stress responses. The identities of the stress-response activators reveal environmental cues that elicit mutagenesis, and are weak links in mutagenesis networks, inhibition of which could slow evolution of resistance during antibiotic therapies. Despite pivotal importance, few identities and fewer functions of stress responses in mutagenesis are clear. Here, we identify the stringent starvation response in fluoroquinolone-antibiotic ciprofloxacin (stress)-induced mutagenesis. We show its role in transient differentiation of a mutable "gambler" cell subpopulation. Stringent activity is induced by reactive oxygen and upregulates two small (s)RNAs that induce the general stress response, which allows mutagenic DNA-break repair. Surprisingly, RNA polymerase and response-activator nucleotide (p)ppGpp promote ciprofloxacin-induced DNA-damage signaling. We propose a model for their regulation of DNA-damage processing in transcribed regions. The data demonstrate a critical node in ciprofloxacin-induced mutagenesis, imply RNA-polymerase regulation of DNA-break repair, and identify promising targets for resistance-resisting drugs.

microbiology↗

bioRxiv2018

Gamblers: an Antibiotic-induced Evolvable Cell Subpopulation Differentiated by Reactive-oxygen-induced General Stress Response

Antibiotics can induce mutations that cause antibiotic resistance. Yet, despite their importance, mechanisms of antibiotic-promoted mutagenesis remain elusive. We report that the fluoroquinolone antibiotic ciprofloxacin (cipro) induces mutations that cause drug resistance by triggering differentiation of a mutant-generating cell subpopulation, using reactive oxygen species (ROS) to signal the sigma-S ({sigma}S) general-stress response. Cipro-generated DNA breaks activate the SOS DNA-damage response and error-prone DNA polymerases in all cells. However, mutagenesis is restricted to a cell subpopulation in which electron transfer and SOS induce ROS, which activate the {sigma}S response, allowing mutagenesis during DNA-break repair. When sorted, this small {sigma}S-response-\"on\" subpopulation produces most antibiotic cross-resistant mutants. An FDA-approved drug prevents {sigma}S induction specifically inhibiting antibiotic-promoted mutagenesis. Furthermore, SOS-inhibited cell division, causing multi-chromosome cells, is required for mutagenesis. The data support a model in which within-cell chromosome cooperation together with development of a \"gambler\" cell subpopulation promote resistance evolution without risking most cells.

microbiology↗

bioRxiv2018

Bacteria-to-human protein networks reveal origins of endogenous DNA damage

DNA damage provokes mutations and cancer, and results from external carcinogens or endogenous cellular processes. Yet, the intrinsic instigators of DNA damage are poorly understood. Here we identify proteins that promote endogenous DNA damage when overproduced: the DNA-damaging proteins (DDPs). We discover a large network of DDPs in Escherichia coli and deconvolute them into six DNA-damage-causing function clusters, demonstrating DDP mechanisms in three: reactive-oxygen increase by transmembrane transporters, chromosome loss by replisome binding, and replication stalling by transcription factors. Their 284 human homologs are over-represented among known cancer drivers, and their expression in tumors predicts heavy mutagenesis and poor prognosis. Half of tested human homologs, when overproduced in human cells, promote DNA damage and mutation, with DNA-damaging mechanisms like those in E. coli. Together, our work reveals DDP networks that provoke endogenous DNA damage and may indicate functions of many human known and newly implicated cancer-promoting proteins.

cancer biology↗